Don't add extra items to sheriff-o-matic history.

BUG=404324
R=ojan@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/479723003

git-svn-id: svn://svn.chromium.org/blink/trunk@180402 bbb929c8-8fbe-4397-9dbb-9b2b20218538